Most viewed questions in Heat Transfer / GO Mechanical

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GATE Mechanical 2014 Set 2 | Question: 44
A material P of thickness $1$ $mm$ is sandwiched between two steel slabs, as shown in the figure below. A heat flux $10$ $kW/m^2$ is supplied to one of the steel slabs as shown. The boundary temperatures of the slabs are indicated ... steady state heat conduction for the configuration, the thermal conductivity ($k$, in $W/m.K$) of material $P$ is _______

A material P of thickness $1$ $mm$ is sandwiched between two steel slabs, as shown in the figure below. A heat flux $10$ $kW/m^2$ is supplied to one of the steel slabs as...

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Arjun asked Feb 19, 2017

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GATE2016-2-45
A reversible cycle receives $40 \: kJ$ of heat from one heat source at a temperature of $127^ \circ C$ and $37 \: kJ$ from another heat source at $97^ \circ C$. The heat rejected (in $kJ$) to the heat sink at $47^ \circ C$ is __________

A reversible cycle receives $40 \: kJ$ of heat from one heat source at a temperature of $127^ \circ C$ and $37 \: kJ$ from another heat source at $97^ \circ C$. The heat ...

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GATE2015-3-12
Saturated vapor is condensed to saturated liquid in a condenser. The heat capacity ratio is $C_r = \displaystyle{\frac{C_{\text{min}}}{C_{\text{max}}}}$. The effectiveness $(\varepsilon)$ of the condenser is $\displaystyle{\frac{1-\text{exp}[-NTU(1+C_r)]}{1+C_r}} \\$ ... $\displaystyle{\frac{NTU}{1+NTU}} \\$ $1 - \text{exp}(-NTU)$

Saturated vapor is condensed to saturated liquid in a condenser. The heat capacity ratio is $C_r = \displaystyle{\frac{C_{\text{min}}}{C_{\text{max}}}}$. The effectivenes...

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GATE Mechanical 2014 Set 1 | Question: 48
A reversible heat engine receives $2$ $kJ$ of heat from a reservoir at $1000$ $K$ and a certain amount of heat from a reservoir at $800$ $K$. It rejects $1$ $kJ$ of heat to a reservoir at $400$ $K$. The net work output (in $kJ$) of the cycle is $0.8$ $1.0$ $1.4$ $2.0$

A reversible heat engine receives $2$ $kJ$ of heat from a reservoir at $1000$ $K$ and a certain amount of heat from a reservoir at $800$ $K$. It rejects $1$ $kJ$ of heat ...

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GATE2016-2-16
Consider the radiation heat exchange inside an annulus between two very long concentric cylinders. The radius of the outer cylinder is $R_o$ and that of the inner cylinder is $R_i$ . The radiation view factor of the outer cylinder onto itself is $1-\sqrt{\dfrac{R_i}{R_o}}\\$ $\sqrt{1-\dfrac{R_i}{R_o}} \\$ $1-\dfrac{R_i}{R_o}^{1/3} \\$ $1-\dfrac{R_i}{R_o}$

Consider the radiation heat exchange inside an annulus between two very long concentric cylinders. The radius of the outer cylinder is $R_o$ and that of the inner cylinde...

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GATE2016-1-49
Heat is removed from a molten metal of mass $2$ $kg$ at a constant rate of $10$ $kW$ till it is completely solidified.The cooling curve is shown in the figure Assuming uniform temperature throughout the volume of the metal during solidification,the latent heat of fusion of metal ( in $kJ$/$kg$) is _________

Heat is removed from a molten metal of mass $2$ $kg$ at a constant rate of $10$ $kW$ till it is completely solidified.The cooling curve is shown in the figureAssuming uni...

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GATE2015-1-8
For flow of viscous fluid over a flat plate, if the fluid temperature is the same as the plate temperature, the thermal boundary layer is thinner than the velocity boundary layer thicker than the velocity boundary layer of the same thickness as the velocity boundary layer not formed at all

For flow of viscous fluid over a flat plate, if the fluid temperature is the same as the plate temperature, the thermal boundary layer isthinner than the velocity boundar...

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GATE Mechanical 2014 Set 2 | Question: 13
The thermal efficiency of an air-standard Brayton cycle in terms of pressure ratio $r_p$ and $\gamma (= c_p /c_v)$ is given by $1-\dfrac{1}{{r_p}^{\gamma -1}} \\$ $1-\dfrac{1}{{r_p}^{\gamma }} \\$ $1-\dfrac{1}{{r_p}^{1/\gamma }} \\$ $1-\dfrac{1}{{r_p}^{(\gamma -1)/\gamma }}$

The thermal efficiency of an air-standard Brayton cycle in terms of pressure ratio $r_p$ and $\gamma (= c_p /c_v)$ is given by$1-\dfrac{1}{{r_p}^{\gamma -1}} \\$$1-\dfrac...

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GATE2016-3-18
For a heat exchanger, $\triangle T_{\text{max}}$ is the maximum temperature difference and $\triangle T_{\text{min}}$ is the minimum temperature difference between the two fluids. LMTD is the log mean temperature difference. $C_{\text{min}}$ and $C_{\text{max}}$ are the minimum ... $C_{\text{max}} \triangle T_{\text{max}}$ $C_{\text{max}} \triangle T_{\text{min}}$

For a heat exchanger, $\triangle T_{\text{max}}$ is the maximum temperature difference and $\triangle T_{\text{min}}$ is the minimum temperature difference between the tw...

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GATE2016-2-35
A circular metallic rod of length $250 \: mm$ is placed between two rigid immovable walls as shown in the figure. The rod is in perfect contact with the wall on the left side and there is a gap of $0.2 \: mm$ between the rod and the wall on the right side. If the ... material of the rod is $200 \: GPa$ and the coefficient of thermal expansion is $10^{−5}$ per $_{}^{\circ}\textrm{C}$.

A circular metallic rod of length $250 \: mm$ is placed between two rigid immovable walls as shown in the figure. The rod is in perfect contact with the wall on the left ...

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GATE2016-3-42
Two large parallel plates having a gap of $10 \: mm$ in between them are maintained at temperatures $T_1 = 1000 \: K$ and $T_2 = 400 \: K$. Given emissivity values, $\epsilon _1 = 0.5$, $\epsilon _2=0.25$ and Stefan-Boltzmann constant $\sigma =5.67 \times 10^{−8} \: W/m^2-K^4$, the heat transfer between the plates (in $kW/m^2$) is __________

Two large parallel plates having a gap of $10 \: mm$ in between them are maintained at temperatures $T_1 = 1000 \: K$ and $T_2 = 400 \: K$. Given emissivity values, $\ep...

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GATE2015-1-9
For an ideal gas with constant values of specific heats, for calculation of the specific enthalpy, it is sufficient to know only the temperature both temperature and pressure are required to be known both temperature and volume are required to be known both temperature and mass are required to be known

For an ideal gas with constant values of specific heats, for calculation of the specific enthalpy,it is sufficient to know only the temperatureboth temperature and pressu...

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GATE2015-3-11
The ratio of momentum diffusivity $(ν)$ to thermal diffusivity $(\alpha)$, is called Prandtl number Nusselt number Biot number Lewis number

The ratio of momentum diffusivity $(ν)$ to thermal diffusivity $(\alpha)$, is calledPrandtl numberNusselt numberBiot numberLewis number

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Arjun asked Feb 24, 2017